i like unique for 45acp. it meters well and works great in that cartridge

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"Gun control: The theory that a woman found dead in an alley, raped and strangled with her panty hose, is somehow morally superior to a woman explaining to police how her attacker got that fatal bullet wound." — L. Neil Smith

The problem with being stupid is you cannot simply decide to stop doing dumb things...

Any fast to medium pistol powder will work. The .45 is a VERY forgiving cartridge. I have used Red Dot, Blue Dot, 700X, W-231, Unique, and probably a few others over the years. All seem to work just fine

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In life, strive to take the high road....It offers a better field of fire.
"Robo is right" Fuzzball

i have found Power Pistol by Alliant to work quite well in all the pistol cartridges i reload and gives very good results as far as accuracy. now how well it meters in a Dillon 550, i have no knowledge of. but you might want to look into it as well.

i have found Power Pistol by Alliant to work quite well in all the pistol cartridges i reload and gives very good results as far as accuracy. now how well it meters in a Dillon 550, i have no knowledge of. but you might want to look into it as well.

i ordered a bit of power pistol from powder valley along with primers and a few other things. if i can remember ill post how it goes when i run a batch of 9mm in the xl650

__________________
"Gun control: The theory that a woman found dead in an alley, raped and strangled with her panty hose, is somehow morally superior to a woman explaining to police how her attacker got that fatal bullet wound." — L. Neil Smith

The problem with being stupid is you cannot simply decide to stop doing dumb things...

Have loaded over 10,000 round of 45 ACP using W-231. When shooting conventional pistol competion using a S&W 25-2, indoors 50 ft, 185 LSWC, 4.4 grains. Using a Dillon 550 never had any problems, and was extremely accurate.
For outdoor 50 yards, used 4.8 grains W-231.
You may need to bump up the powder usage to make a 1911 function for softball, but the powder always fed correctly, and when measured did not vary.
YMMV
Earl

+1 on win 231. I use it exclusively on 9, 40 and 45. I have a 550b and it meters great. Recently though my reloading shops have been sold out of 231 for a couple months. Ive got 3 1/2 pounds left. Ugh. Had the owner of the shop talk me into trying tite group so I bought a pound. He warned me to pay attention to the stuff because it doesn't take very much grain wise compared to others. Haven't loaded any yet.

Jon I've read on this forum about powder valley. Looked at the site and was surprised how cheap it was. Then I clicked checkout and passed out when I saw the hazmat fee. When you order I'm guessing your doing serious bulk?